Joining battle to make London’s black cabs green

Andy Goundry:

photo: the Guardian
two of Londons iconic landmarks.         photo:Guardian

Boris Johnson has spoken. London’s Mayor wants Central London to be an Ultra-Low Emission Zone by 2020 and the capital’s iconic (mostly black) cabs will have to play their part.

He is adamant that all new London taxis presented for licensing from January 2018 onwards will have to be zero-emission capable; in other words, they will have to be able to run solely on battery power in certain areas of Britain’s biggest city. Conscious that they too need to take action in the wake of the European Commission’s decision to launch legal proceedings against the UK over air quality levels, other urban authorities are watching what happens in the capital with keen interest.

Totally zero-emissions taxis are unlikely to be seen in number any time soon, given the present state of battery technology: it is hard to imagine a London cabbie – whose livelihood depends on his cab being available for a full daily shift – being prepared to accept the “range anxiety” which presently limits the uptake of electric cars amongst the general public. And yet in many respects city centre cab operation, be it London or any other highly urbanised area, presents an ideal operating ground for electric traction, given the inevitable frequent brake applications in stop / start traffic which should give a healthy dose of charge regeneration into the batteries. Even with this high level of brake regeneration however, adequate battery capacity to permit full electric operation for the duration of an entire driving shift is unlikely. So some form of back-up power is probably necessary – step forward the range extended electric vehicle: a variant on the hybrid theme where a small-output internal-combustion engine is used to top-up the batteries as required, rather than the traditional hybrid’s larger petrol or diesel engine which can provide the entire power under certain circumstances to drive the vehicle.

Manufacturers are already busy developing such cabs that meet Johnson’s requirements and which also retain the traditional profile and style of London taxis. Pleasingly, most of the front-runners in the race to win a share of the future London taxi market are either British manufactured or at least British engineered. The long-established black cab manufacturer, Metrocab, have teamed with two UK-based technology companies, Ecotive and Fraser-Nash Research, to develop the Range Extended Electric (REE) Metrocab fitted with a lithium-ion battery, an electric motor for each of the rear wheels and a 1.0-litre petrol range-extender engine coupled to a generator.

The Range Extended Electric Metrocab undergoing trials. photo: Metrocab
The Range Extended Electric Metrocab undergoing trials.                                           Photo: Metrocab

“Instantly recognisable as a London cab, with a panoramic glass roof for views of the city, it offers for no price premium completely new levels of economy, emissions and passenger comfort and is ready to enter service this year,” says Metrocab Chairman, Sir Charles Masefield. With CO2 emissions set at a modest 50g/km, the REE Metrocab is more than three times more fuel-efficient than conventional London taxis, claims the manufacturer and should typically save the driver between £30 and £40 a day. It can be recharged at home from a standard domestic power supply and has a claimed range of up to 350 miles. The new Metrocab should start trials on London’s streets during this coming summer.

the Metrocabs electric drivetrain. photo:Metrocab
the Metrocabs electric drivetrain.    Photo:Metrocab

Metrocab will not have things all its own way however. Already a major UK car manufacturer, Nissan is working with Coventry-based ADV Manufacturing to produce its new Taxi for London, which is set to appear on the capital’s streets at the end of the year. The two companies are setting up a taxi factory in the city, which has a long history of cab production, in a £6m joint venture marking a further boost for the UK automotive industry. The base vehicle will be shipped over from Spain for final assembly at the ADV Midlands plant where it will be fitted with new bodywork with a taxi-type interior plus revised suspension and steering. Based on the NV200 platform, Taxi for London has been designed in London for London by Nissan Design Europe in Paddington, which is also responsible for the Qashqai and the Juke. The first model to roll off the line ready for delivery in December will be petrol-powered. Nissan will launch an all-electric version in 2015 with the batteries manufactured in Sunderland. The Nissan/ADV project is being supported with a loan of nearly £4m through the Advanced Manufacturing and Supply Chain Initiative, the UK government’s job creation fund for manufacturing.

Nissans Taxi for London   photo: Nissan
Nissans Taxi for London.                    Photo: Nissan

Also based in Coventry, and acquired by Chinese manufacturer Geely just over a year ago, the London Taxi Company – makers of the familiar TX4 cab – also plan to have a compliant vehicle by the start of 2018. “We will meet this challenge by offering a new, purpose-built, plug-in range-extended electric hybrid taxi,” promises Executive Vice-President, Peter Johansen.

Interestingly, and rather worryingly for UK manufacturers, the Chinese seem to be developing some prowess in electric vehicle operation here in the UK. BYD, the Chinese vehicle manufacturer, supplied two full electric buses to a London operator in late 2013, which are apparently running well, whilst internationally renowned financier Warren Buffet is backing a plan to put 20 BYD full-electric taxis, each with a claimed range of 186 miles, into service in London during 2014.

Whatever the final result, with such strong competition, the race to turn black cabs green looks likely to be closely fought.


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  1. Good question Bobby. As far as I know, the Mayors statement was aimed at all London cabs, not just the city centre. My guess would be that the existing low emission zone would form the boundary.

  2. Time for the Gas turbine, much more efficient than the reciprocating engine and ideally suited to generator duties, and being constant burn cleaner than any other engine

    • Points well made, Stewart, also turbines can run on a wide range of fuels.
      Many hybrids are indeed set up to run only at one or more set speeds, these speeds being optimised for the greatest engine efficiency.

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